SLC12A3 and Hypokalemia: Gitelman syndrome is an autosomal recessive tubulopathy arising from mutations in the SLC12A3 gene encoding the thiazide-sensitive NaCl cotransporter.1,2 The syndrome is characterized by metabolic alkalosis, hypokalemia, hypomagnesemia, and reduced urinary calcium excretion.1 While often benign, rare associations with arrhythmias and sudden cardiac death have been reported.3,4 No known association between GS and cardiomyopathy exists.